ProPublica’s Documenting Hate collaboration comes to a close next month after nearly three years. It brought together hundreds of newsrooms around the country to cover hate crimes and bias incidents.

The project started because we wanted to gather as much data as we could, to find untold stories and to fill in gaps in woefully inadequate federal data collection on hate crimes. Our approach included asking people to tell us their stories of experiencing or witnessing hate crimes and bias incidents.

As a relatively small newsroom, we knew we couldn’t do it alone. We’d have to work with partners － lots of them － to reach the biggest possible audience. So we published a tip form in English and Spanish, and recruited newsrooms around the country to share it with their readers.

We ended up working with more than 180 partners to report stories based on the leads we collected and the data we gathered. Partnering with national, local and ethnic media, we were able to investigate individual hate incidents and patterns in how hate manifested itself on a national scale. (While the collaboration between newsrooms is coming to an end, ProPublica will continue covering hate crimes and hate groups.)

Our partners reported on kids getting harassed in school, middle schoolers forming a human swastika, hate crime convictions, Ivy League vandalism, hate incidents at Walmarts and the phrase “go back to your country,” to name just a few. Since the project began in 2017, we received more than 6,000 submissions, gathered hundreds of public records on hate crimes and published more than 230 stories.

Projects like Documenting Hate are part of the growing phenomenon of collaborative data journalism, which involves many newsrooms working together around a single, shared data source.

If you’re working on such a collaboration or considering starting one, I’ve written a detailed guidebook to collaborative data projects, which is also available in Spanish and Portuguese. But as the project winds down, I wanted to share some broader lessons we’ve learned about managing large-scale collaborations:

Overshare information. Find as many opportunities as possible to explain how the project works, the resources available and how to access them. Journalists are busy and are constantly deluged with information, so using any excuse to remind them of what they need to know benefits everyone involved. I used introductory calls, onboarding materials, training documents and webinars as a way to do this.

Prepare for turnover. More than 500 journalists joined Documenting Hate over its nearly three-year run. But more than 170 left the newsrooms with which they were associated at the beginning of their participation in the project, either because they got a new job, were laid off, left journalism or their company went under. Sometimes journalists would warn me they were leaving, but most of the time I had to figure it out from email bounces. Sadly, it was rare that reporters changing jobs would rejoin.

Be understanding about the news cycle. Intense news cycles, whether it’s hurricanes or political crises, mean that reporters are not only going to get pulled away from the project but from their daily work, too. Days with breaking news may mean trainings or calls need to be rescheduled and publication dates bumped back. It’s important to be flexible on scheduling and timelines.

Adapt to the realities of the beat. It’s not uncommon for crime victims, especially hate-crime victims, to be reluctant to go on the record or even speak to journalists. Their cases are difficult to report out and verify. So like in a lot of beats, a promising lead doesn’t guarantee an achievable story. Crowdsourced data made the odds even longer in many cases, since we didn’t receive tips for every partner. That’s why it’s important to set expectations and offer context and guidance about the beat from the outset.

Expand your offerings. Given the aforementioned challenges, it’s a good idea to diversify potential story sources. We made a log of hate-crime-related public records requests at ProPublica for our reporting, and we made those records available to partners. We also offered a weekly newsletter with news clips and new reports/data from external sources, monthly webinars and guidance on investigating hate crimes.

Be flexible on communication strategies. Even though Slack can be useful for quick communication, especially among large groups, not everyone likes to use it or knows how. Email is what I’ve used most consistently, but reporters’ inboxes tend to pile up, and sometimes calling is easiest. Some journalists are heavy WhatsApp users, and I get through to them fastest there. Holding webinars and trainings is helpful to get some virtual face time, and sending event invites is another way you can get someone’s attention amid a crowded inbox. It’s useful to get a sense of the methods to which people are most responsive.

Celebrate success stories. There is a huge amount of work that doesn’t end up seeing the light of day, so I make an effort to signal-boost work that gets produced. I’ve highlighted big stories that ProPublica and our partners have done to show other partners how they can do similar work or localize national stories. Amplifying these stories by sharing on social and in newsletters, as well as featuring them in webinars, can help inspire more great work.

Be diligent about tracking progress. Our database software has a built-in tracking system for submissions, but I separately track stories produced from the project, news clips and interviews that mention the project, as well as impact from reporting. I keep on top of stories partners are working on, and I also use Google Alerts, internal PR emails and daily clip searches.

Evaluate your work. I’m surveying current and past Documenting Hate participants to get feedback and gauge how participants felt about working with us. I’m also going to write a post-mortem on the project to leave behind a record of the lessons we learned.